Retiring cam



May 28, 1929.

w. BRUNS RETIRING CAM Filed Oct. 27, 1927 iii-777751 6 A /0 :J 77 M66 6INVENTOR' Y E N R 0 w A WM @AMKL.

latent ed may I k i i UNI-TED STATES PATENT (OFFICE.-

WILDIAM BBUNS, OF YORK, Y., ASSIGNOR TO OTIS ELEVATOR COMPANY, OF

' NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

nnrmme our.

Application ma October-27, 1927. Serial No} 229,175

r This invention relates to retiring cams 14. as clearly shown inFigures 2 and 3. and particularly to retiring cams for use A pa1r oftriangular levers are pivotally i l t stem 4 supported at their apexeson the upper por- In the operation of elevators it is frequenttron ofplate 13 by means of a pin 16. A 5 ly desirable to operate door locks,door closer s milar pair of triangular levers 17 are. in engines, andthe like from the elevator car. like manner fpivotally supported on thelow- To accomplish this a retiring cam may be e por lon o plate 13 bymeans of a pin 18. mounted on the elevator car for coopera- Thetriangular levers constitute, in efiect, 'tion with the devices at thevarious landings. right angle bell cranks with their fulcrums 10 Whenthe elevator car is running, the re- ,at the pivotal supports 16 and 18.Collars tiring cam is retracted so that it clears the 20' serveto spacethe triangular levers of devices located in thehatchway and when eachpairjfrom each other, and collars 21 the car stops at a landing,the-retiring cam serve to space/each pair of triangular levers isextended to operate the devices .at that from plate 13. Cotter pins 19hold the le- 15 l di vers securely in position. A cam plate 22 is Onefeature of the invention is the proprovided with two supporting arms 23rigvision of a retiring cam that exerts a conldly secured to the camplate by riveting over stant operating force as it moves from itsportions 24 of arms 23. Two supporting retracted position to itsextended position. arms 23 of the camplate are pivotally con" '20 Asecond feature ofthe invention is the nectedto corresponding vertices oftrianguprovision of a retiring cam that occupies lar levers 15 and 17 bymeans of pins 25. a minimum of space, and requires a mini-. A cam weight26 is pivotally connected to mum of force to operate. it. correspond ngvertices of triangular levers v A third feature of. he invention is the15 and 17 by means of pins 27.. Cam 25 provision of a retirin cam thatis of simweight 26 is provided with recesses 29 ple, compact and stur yconstruction, reliatoaccommodate the triangular levers. By

' ble in operation, and which may be operthis construction downwardmovement of the ated an unlimited number of times without weight causesthe triangular levers to swing replagement y about their supportingpins-and move the 30 Other features and advantages will become .cam toits extended position.

apparent from the following description and" Aretiring cam magnet 28 formoving the appended: claims. i caminto itsretracted position isadjustably I th drawings: mounted upon the car 10. The constructionFigure 1 illustrates the retiring cam apof themagnet is clearly shown inFigure 4. 35 plied to an elevator car and shows the cam The magnet isprovided with a coil 30 and in its retracted position; an armature 31,the armature being pivotally Figure 2 is a view in frontelevation ofconnected to the magnet frame by means of the retiring cam in itsextended position; a pin 32. A. dash-pot, which serves both to Figure 3is a view in side elevation of the limit the movement of armature 31 andto 40 retiring cam with portions .broken away to retard its motion inone,' direction, is supillustrate certain structural details; ported bythe magnet frame. ,-A dash-pot Figure 46 is a view in part'se'ctlonalelecylinder 33 is formed integrally with the vation of the cam'operating magnet; magnet frame, although 'it may be formed Figure 5 is aview in front elevation of 'a as a separate element. A piston 34;. is

45 modification of the retiring cam in its explaced within the cylinder33 for reciprocat- 1'00 tended position; and a ing movement. Piston rod35, which is piv- Figure 6 is a view in side elevation of the otallyconnected to piston 34, is provided modification of the retiring camwith porwith a rod 36 screwed into-itsend. Armations broken away toillustrate certain structure 31 is operatively connected to rod 36 50tural details. by means of a pivot pin 37,- the pin being Referring toFigure 1, an elevatorcar 1O bored to accommodate rod 36. Piston rod isprovided with a retiring cam 11 arranged 35 serves as one abutment forarmature 31 to operate a ooor lock operating lever 12. and nuts 38 asthe other abutment. Buffer -Retiring cam 11 is provided with a plate 13springs 40 are placed between the armature" '55 securely fastened toelevator car 10 by screws and the .abutments to lessen the impact of nothe armature as it swings from one abutment to the other to move thepiston. A

lbell crank 41 is ,pivotally supported by car 10, one arm 42 of thebellcrank being connected to cam weight 26 by .a chain 44, the

other arm 43 of the bell crank being pivotally connected to armature 31by means of a I rod45.' The point. at which rod 45 is connected toarmature 31 maybe varied by changing the pivotal connection ofrod 45from one to another of holes 46'. The motion of piston 34 in its inwardmovement is limited by the end of the dash-pot cylinder and in itsoutward movement, by dash- .pot cylinder head 47. Rubber washers '48.

are provided to absorb the impact caused by piston '34 being broughttoastop at the ends I of its movement; A ball check valve 50- is screwedinto passage 52,- the passage 52'be'- f ingconnected with the inter1or,of the cylinder by means of passage 53. An ape'rtured plug 55 isscrewed into the end of. passage y The operation of the retiring cam -1Sas follows:

Assume the car to be at .a landing asshown in Figure 1 and magnet 28 tobe energized. The magnet, acting through rod 45,

a bell crank 41 and chain 44, holds cam weight 26"at its upper position,thus holding cam 'plate 22 in its retracted position. To cause cam plate'22 to operate lever 12, the magnet is deenergized, permittin -26 to-move downwardly P11111110- the chain cam weight.

ownwardly withit. As the weight moves itswings triangular levers 15 and17 about their ivotal supports to force cam :plate 22 into its extendedposition. At the same time, armature 31' swings to its outward positionand as it approaches the end -,0f 1tS outward movement it-engages bufferspring 40, causing piston 34 to moveto. the right as viewed in Figure 4.The iston upon engaging head 47, through ru ber washer 48, stops theweight in its downward movement. A stop '56, provided with a bufferspring 57,;is supported: upon plate 13 by l'iV- eting over. pro ectinportion 58 ofstop 56,

the stop serving .un er any circumstances to prevent excess downwardmovementpf the. cam weight. The weight is gentlybrought to a stop by thesuction created'in the dash-.

' apertures, .within passage engagesbufier spring 40 allows arapid-expot as the piston movesto-the ri ht. The

rce of thissuction ma be varied y inserting plugs, formed wit larger orsmaller Themirestricted movement of the armature before it tension ofcam plate 22, while the dash-pot acting at. the end of the armature.movement prevents weight26 from. being broughtto a stop too suddenly.

To retire cam .plate' 22, the, magnet is again* energized causing thearmature swing to its inner position.--;We1gh t 26 is lifted positionswinging triang ularlevers 15 and 17 about their pivots,

causing the cam plateto moveiinto. itSFIB tracted' position. Thearmature in swing- 1 ng lnward-ly engages buffer spring 40, causmgp1ston34 to moveto' the left as viewed in Figure l. The piston uponengaging the 1 end of the cylinder stops weight 26 initsup wardmovement. Stop 56 againacts. as a safety to prevent excess upwardmovement. The movement of'the piston to the left is substantiallyunretarded but this may be governed: by varying the sizeof the ballcheck valve employed.

Referring toFigures 5 and cam-1s illustrated in which a spring, insteadof a weight, is used to move the cam plate to its extended position. Aplate 60' is securely fastened to car 61 by means of screws 62.Triangular levers 63 are pivotally supported on the upper portion .ofplate 60-and trian 'gular levers 64 are 'pivotally supported on.

the lower-l'portion ofplate 60. A cam plate 65,:provided with rigidprojecting arms 66, is plvotally supported at corresponding-vet 6, aretiring El) tioes of tnangularlevers"63 and 64 by pins .67. far thestructure isfidentical with that lllustratcdjin'Figures 2 and 3. Howvever, of the weight, a bar 68 is used" i to connect correspondingvertices-7O of the triangular levers.v A U-shaped bracket 71 is securedto bar 68 hy means of a screw 72. A rod 73 1s pivotallyconnected at oneend to;

bracket 71 by pin74 and is guided at its magnet, bar 68 is pulled toitsupper position I against the compression of spring. 7

Upon deener'gization of. the magnet, the spring," with bracket '75 as anabutment, acting-agamst seat 76. forces bar 68 to'i-ts lowerposition,.causing'triangular levers 63 and 64 7, movmgjcam-plate 65 toits retracted position. no

to move -about their pivotal. supports. As '1 the levers so move, camplate 65 is forced into its extended-position.

= n is to be noted that with' the retiring cam of,this invention,- asillustrated in Figure .1 the force exerted in .ahori'zontal direcm.

6y the cam'plateis constant throughout.

tion its movement from retracted to extended 'tion. .As the weight fallsunder the in-.

uenoe of .gravi all? acts. through" the bell crank levers toove the camplate. Thus,

' the arms ofi the bell crank lever 'to .be'of equal length,the verticalcomponent of the movement of the cam weight is equal to the horizontalcomponent of the movement of the cam plate. Then since the: cam 139plate; actuating Weight constant, the force that the cam plate may exertin a horizontal direction is also constant.

In the case Where a spring is employed, substantially the same resultsare obtained provided the spring is of suflicient length and undersufficient initial compression.

Attention is called to the fact that as tlie force exerted by the cam isconstant, it is only necessary to design a cam so that this constantforce will overcome the maximum opposing force, and .it makes nodifference in What portion of its movement the cam contacts with theelement to be moved or operated.

As many changes could be made in the above construction and manyapparently widely dilferent embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense. I

What is claimed is:

1. A retiring cam comprising; a cam means for moving thecam plate to itsextended position; a substantially right angle bell crank leverconnecting said cam plate and said actuating means; and retarding meansbrought into action as the cam plate nears its extended position tocause a gradual stop of said cam plate and actuating'means.

angle bell crank lever,

2. A retiring cam comprising; a support; a cam plate; a cam Weight formoving said cam plate to its extended position; a right fulcrumed onsaid support, and. connecting said cam plate and said cam weight; adash-pot; and a lost motion connection between said cam weight anddash-pot to cause the operation of the dashpot just before the cam platereaches its extended position to. bring said cam plate and Weight to agradual stop.

3. A retiring cam comprising; a support; a cam plate; a cam weight formoving said cam plate to its extended position; a pair of right anglebell crank levers, fulcrumed on said support, and connecting said camplate and said cam weight; a member connected to said weight to be movedthereby about a pivot during extension of said cam plate; a daslnpothaving an extended piston rod; and a butler spring arranged on said rodin the path of movement of said member about said pivot, said springbeing spaced from said member when the cam plate is in retractedposition to allow rapid extension of the cam plate and upon engagementby said member just before the cam plate becomes fully extended causingthe operation of the dash-pot to to a gradual stop.

In testimony whereof, I'have signed my name to this specification.

WILLIAM BRUNS.

bring the Weight and cam plate

